Towards zero CO2 emissions in the production of methanol from switchgrass. CO2 to methanol

In this work an integrated facility is proposed that produces methanol from switchgrass and uses the captured CO2 to enhance the production capacity by 50% via CO2 hydrogenation. The process consists of two sections, biomass processing to syngas and its conversion to methanol, and the electrolytic section where hydrogen is produced to hydrogenate the CO2 that has been captured during syngas cleaning. The integrated facility produces up to 207 Mgal/yr of methanol and 318 kt/yr of oxygen, but requires a large amount of electricity to generate the hydrogen. Thus, it can only be used in regions where wind velocity is above 8 m/s and solar radiation is above 5 kWh/m2/day such as in the Midwest of US, certain regions in China or in the South of Europe. The investment is high, around 1000 M€, but the production cost of methanol is promising, 0.25-0.35 €/kg with a high production capacity.